These CentreCOM Micro Transceivers are 10Base-T compliant transceivers designed to reduce Ethernet cabling costs. Compact size allows these transceivers to connect directly to the workstation, bringing thin Ethernet or Unshielded Twisted Pair (UTP) wiring directly to the workstation. With UTP and inexpensive coax network media, distances up to 100 meters between workstations can be supported using UTP, and up to 185 meters using coax. On all models Signal Quality Error (SQE)/Heartbeat test can easily be enabled or disabled via an externally accessible switch. Additionally, all models have integral jabber lock-up prevention circuitry and a loopback function. This function emulates coaxial media where transmitted packets are looped back to the receive side. Local Area Network (LAN) controllers can use the loopback feature to determine if a Media Attachment Unit (MAU) is connected and operational. The AT-MX20T transceivers incorporate other functions that offer improved network reliability for workstations. The 10Base-T link integrity test function provides a continuous test of the connection to the multiport repeater.